Such milling cutters typically comprise an annular cutter body having a plurality of identical segments equally spaced about the inner circumference of the cutter body. Each segment having typically three or more cutting inserts secured to it, with each cutting insert intended to mill a particular feature of the complex profile. Inevitably, at least one of the cutting inserts of each segment has a different geometry from the other cutting inserts of that segment. Consequently, a stock of at least two types of cutting inserts has to be kept and care has to be taken when replacing a worn cutting insert of a segment not to replace it by a cutting insert of a different geometry.
In many such milling cutters, tangential cutting inserts are used. Tangential cutting inserts, also known as on-edge, or lay down, cutting inserts, are oriented in an insert holder in such a manner that during a cutting operation on a workpiece the cutting forces are directed along a major (thicker) dimension of the cutting insert. An advantage of such an arrangement being that the cutting insert can withstand greater cutting forces than when oriented in such a manner that the cutting forces are directed along a minor (thinner) dimension of the cutting insert.